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A frog's ear drum works in very much the same way as does a human eardrum. It is a membrane that is stretched across a ring of cartilage like a snare drum that vibrates. Crossing the middle ear chamber there is an ossicle called the columella that is connected to the tympanum, and another ossicle, the operculum, that connects this to the oval ...
Frogs have no tail, except as larvae, and most have long hind legs, elongated ankle bones, webbed toes, no claws, large eyes, and a smooth or warty skin. They have short vertebral columns, with no more than 10 free vertebrae and fused tailbones (urostyle or coccyx). [ 47 ]
A true endoskeleton is derived from mesodermal tissue. In three phyla of animals, Chordata, Echinodermata and Porifera (), endoskeletons of various complexity are found.An endoskeleton may function purely for structural support (as in the case of Porifera), but often also serves as an attachment site for muscles and a mechanism for transmitting muscular forces as in chordates and echinoderms ...
Mounted skull of a python with disarticulated upper and lower jaw joints. In snakes, the columella would be attached directly to the quadrate bone (c). Snakes have lost a tympanic membrane, and hence a distal attachment for the columella. The columella is instead connected to the quadrate bone of the jaw. Thus, snakes are able to detect and ...
The skeleton has primitive features, but has mostly lost the salamander-like traits of its ancestors. It has a skeleton designed to absorb the force of jumping with its hind legs and tail. It also has long hip bones, long hind leg bones, and long ankle bones, all similar to modern frogs, and is as of 2009 the earliest true frog. [1]
Male Rana temporaria calling in a garden pond in Jambes, Belgium. The common frog or grass frog (Rana temporaria), also known as the European common frog, European common brown frog, European grass frog, European Holarctic true frog, European pond frog or European brown frog, is a semi-aquatic amphibian of the family Ranidae, found throughout much of Europe as far north as Scandinavia and as ...
Common frog (Rana temporaria) tadpole. A tadpole or polliwog (also spelled pollywog) is the larval stage in the biological life cycle of an amphibian.Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial.
The evolution of the mammalian middle ear appears to have occurred in two steps. A partial middle ear formed by the departure of postdentary bones from the dentary, and happened independently in the ancestors of monotremes and therians. The second step was the transition to a definite mammalian middle ear, and evolved independently at least ...